Cutter chain



June 13, 1950 L. E. SIMMONS 2,511,132

CUTTER CHAIN Filed Oct. 5, 1945 [ZZZ/6221202: E. 522222220225.

Patented June 13, 1950 UNITED STATES PATENT OFFICE Pennsylvania Application October 5, 1945, Serial N 0. 620,487

4 Claims.

This invention relates to cutter chains and more particularly to an improved cutter bit and bit holder especially designed for use in the sock ets or the standard blocks of a conventional mining machine cutter chain.

In a conventional mining machine cutter chain there is provided a series of chain blocks pivotally connected together by strap links and the blocks have right-ang1e bit-receiving sockets normal to the path of travel of the chain and of generally rectangular cross section. Standard set screws threaded in the blocks at the front sides of the sockets serve to secure the shanks of standard single pointed bits in the chain block sockets. Under certain mining conditions, it is desirable to employ, in place of standard shanked bits, relatively small, plural pointed, reversible cutter bits which are of relatively inexpensive design and which may be readily discarded when worn, thereby eliminating the need for resharpening and its attendant cost. Several known attempts have been made to support such relatively small plural pointed bits on the standard chain blocks of a conventional cutter chain but to obtain the strength and durability desirable, it was found necessary, in most instances, to provide special relatively expensive chain blocks for receiving special clamps or holders for supporting the relatively small plural pointed bits in cutting position on the blocks. Known designs of hold ers for such plural pointed bits, when used in the sockets of standard chain blocks, in certain instances, were found to be comparatively bulky outside of the block socket, presenting a relatively wide outer supporting head for the bits or other wide parts whichmust be dragged through the kerf during the cutting operation, thereby reducing efiiciency and resulting in relatively rapid wear of the holder. Further, in other known designs, the cutter bits were held in position by relatively complicated plural-part bit holders or clamps received in the block sockets and which, due to the relatively small cross section of the block sockets, necessarily had to be relatively small in cross section resulting in structures which were comparatively weak.

In accordance with the present invention, the improved relatively small, plural pointed, reversible cutter bits are held in cutting position on the blocks of a standard cutter chain in an improved manner so that the cutter bits, when supported on the blocks, are nearly as strong and durable as standard single pointed shanked bits and substantially stronger and more compact than known types of detachable bit holders for use in the sockets of standardchain blocks. The cutter bits are of a novel design and are received in the block sockets with their rear sides enga ing the rear socket walls and are held in position in the block sockets by one-piece holders which are disposed in the block sockets in advance of the cutter bits and having interlocking engagement with the cutter bits. These one-piece front holders are engaged by the standard set screws on the blocks, and are clamped in position in the block sockets in a manner similar to a standard single pointed shanked bit. In accordance with a preferred embodiment of the invention -the cutter bits may be of generally triangular shape in side elevation and haverelatively inclined, oppositely directed cutting portions, each of which resembles the cutting portion of a standard shanked bit, and the cutter bit is recessed at its central portion and the holder projects within the bit recess to interlock the bit and holder together. The inner inactive cutting portion of the bit is received in the block socket at the rear side of the holder with its rear side in engagement with the rear socket wall and the active cutting portion projects forwardly and outwardly into cutting position with respect to the chain block. The holder is no greater in width than the width of the cutter bit and when the bit and holder are in engaged position in the block socket, their general contour resembles the contour of a standard single pointed shanked bit, and due to the novel bit and holder shape, relatively great strength is attained so that the resulting structure is nearly as strong and compact as a standard shanked bit. By locating the relatively narrow holder in advance of the cutter bit and'substantially within the block socket, the rear side of the bit, where it projects outwardly from the block, is free and clear, enabling the bit to pass smoothly and with comparative ease through the coal. In a preferred embodiment, the bit holder may rest on the exterior of the chain block at the'front side of the socket properly to gauge the projection of the active cutting end of the bit from the block; while in another embodiment, the front face of the cutter bit may rest against the outer edge of the front wall of the block socket to obtain the proper bit gauge. In both embodiments, due to the improved construction, a wedging action is attained which tends to hold the bit and holde in the block socket even when the set screw becomes slightly loose. In one embodiment, the cutter bit may have side shearing edges extending rearwardly of the front cutting edges and there are pockets in the sides of the bit inwardly of the shearinge'd'ges which tend to aid in the carrying out of the coal cuttings'from the kerf.

It is accordingly an object of the present invention to provide an improved discai'dable cutter bit of the small, plural pointed, reversible type and a cooperating bit holder of an: improved design whereby the bit may be held in cutting position on a standard chain block in an improved manner. Another object is to provide an inn proved cutter bit and holder construction especially designed for use in the right-angle socket of a standard chain block, which cutter bit and holder are not only relatively rugged and durable but which may be manufactured at relatively low cost. Still another object is to provide an improved cutter bit of the small, plural pointed, reversible type having improved means adapted for interlocking engagement with a bit holder. A further object is to provide an improved cutter bit holder especially designed for use in a standard block socket. A still further object is to provide an improved plural pointed reversible cutter bit and bit holder which, due to their improved design, are nearly as strong and compact as a standard single pointed shanked bit, and which, like a standard shanked bit, may be inserted in the socket of a standard chain block and held in position therein by a standard set screw. Still another object is to provide an improved cutter bit having side shearing edges extending rearwardly and inwardly from its front cutting edges and having side pockets inwardly of the shearing edges for aiding in the conveying of the coal cuttings from the kerf. These and other objects and advantages of the invention will, how-ever, hereinafter more fully appear.

In the accompanying drawing there are shown for purposes of illustration two forms which the invention may assume in practice.

In this drawing:

Fig. 1 is a side elevational view of a standard chain block having associated therewith a bit and holder constructed in accordance with a preferred illustrative embodiment of the invention.

Fig. 2 is a cross sectional view taken substantially on line 22 of Fig. 1, showing the chain block, holder and cutter bit in front end elevation.

Fig. 3 is a vertical longitudinal sectional view taken substantially on line 33 of Fig. 2.

Fig. 4 is a horizontal sectional view taken on line 4-4 of Fig. 3, showing the chain block in top plan.

Fig. 5 is a detail horizontal sectional view taken on line 5-5 of Fig. 3.

Fig. 6 is a perspective view of the improved bit holder.

Fig. '7 is a perspective view of the improved cutter bit.

Fig. 8 is a sectional view similar to Fig. 3, illustrating a modified holder and bit construction.

Fig. 9 is a fragmentary front end elevational view of the structure shown in Fig. 8.

Fig. 10 is a horizontal sectional View taken on line H]l of Fig. 8.

Fig. 11 is an elevational view illustrating the front face of the modified cutter bit shown in Fig. 8.

Fig. 12 is a perspective view of the modified bit holder.

Fig. 13 is a perspective view of the modified cutter bit.

In both illustrative embodiments of the invention, the improved cutter bit and holder are shown associated with a standard chain block I of a mining machine cutter chain. The chain block is pivotally connected by hinge pins 2 to usual strap links 3, and has, at its base, lateral gibs 4 adapted for reception in the guideways of a conventional mining machine cutter bar. The chain block has a lateral lug formed with a right-angle socket 6 normal to the path of travel of the cutter chain and the block socket is of generally rectangular shape in cross section, having plane front and rear walls 1 and 8 and parallel side Walls 9, 9, the latter, in a standard block, being laterally enlarged at In for breaching purposes in a well known manner. Threaded within an opening II in the block lug at the forward side of the socket is a standard set screw 12. As is usual in standard chain blocks, the block lug is formed at the rear side of the socket with an unused threaded opening in which the set screw 12 may be placed to hold the holder and bit in reversed position in the block socket when the direction of travel of the cutter chain is reversed and since this reversible feature is common in conventional cutter chains, further mention thereof is herein unnecessary. Evidently, the improved cutter bit and holder may be assooiated with chain blocks of cutter chains of other types.

Now referring to the preferred embodiment of the invention shown in Figs. 1 to 7 inclusive, it will be observed that an improved holder, generally designated I3, is associated with an improved cutter bit, generally designated [4. The improved bit holder has a rectangular shank l5 received in the block socket and engageable at I6 at its rear side of its inner end with the rear wall 8 of the block socket, and an outer ledgelike portion I! rests at [8 against the exterior surface of the block lug in advance of the front wall I of the block socket. The outer portion of the holder has a longitudinal slot or groove I9 centrally between its sides and this slot opens through the rear side of the holder, as shown. The slot is provided with a bottom wall 20 which is outwardly and forwardly inclined and alined with an inclined surface 2| at the rear side of the inner portion of the holder shank. The surface 2|, in this instance, extends across the full width of the holder and serves to provide an abutment for the cutting face of the cutter bit as hereinafter described. The holder slot [9 provides spaced side projections .22, 22 which extend rearwardly and which are formed with rounded or curved surfaces at 23 at their rearward sides, and have inwardly and forwardly inclined rearwardly facing surfaces 24 disposed at an angle with respect to the longitudinal axis of the holder for a purpose to be later explained. The improvide cutter bit [4 is of the relatively small,

plural pointed, reversible type which, due to its relatively inexpensive design, may be readily discarded when worn. The cutter bit has a body preferably generally triangular in shape in side elevation providing an elongated plane cutting face 25 at the base of the triangle, and relatively inclined rear walls 26, 26 disposed at an obtuse angle are formed at the sides of the triangle and joined at the apex side of the triangle by a curved surface 21. The plane cutting face 25 terminates in cutting points 28, 28 at the opposite extremities of the bit body at the same side of the bit, and side surfaces 29, 29 of the cutting ends recede rearwardly and inwardly from the cutting edges and join along the rear wall of the bit body. The cutter bit is suitably recessed for interlocking engagement with the holder in an improved manner, as hereinafter explained, and is herein formed with side recesses 30, 30 opening forwardly through the forward bit face and separated by a relatively narrow web 3|. The side walls 32, 32 of the recesses are relatively inclined and diverge forwardly and outwardly with respect to the rear of the bit body and are joined near the back of the bit by rearward curved walls 33. When the cutter bit and holder are placed together, the side projections 22 of the holder are received in the bit recesses 30 with their rearwardly facing inclined surfaces 24 engaging the forwardly facing inner walls 32 of the recesses, as clearly shown in Fig. 1. When the holder and cutter bit have been inserted in position on the chain block, the inner inactive cutting end of the bit is disposed in the block socket with its front face resting against the holder surface 2! and with its rear surface against the rear wall 8 of the block socket. The set screw l2, when tightened, engages the front side of the holder shank and forces the rear side of the inactive cutting portion of the cutter bit firmly against the rear wall 8 of the block socket. When the cutter bit is so positioned, the narrow bit web 35, intermediate the side recesses, is received in the holder slot 19 in the manner shown in Fig. 5, in interlocking relation with the holder. The inner inclined surfaces 24 of the holder projections engaging the inclined inner walls 32 of the bit recesses serve to hold the cutter bit against outward release from the block socket, and even in the event the set screw becomes slightly loose, the engaging inclined surfaces on the holder and bit afford a wedging action which tends to hold the holder and bit against outward release from the block socket. The forward portion of the holder and the rear portion of the cutter bit are formed to fit snugly the socket walls, as shown in Fig. 5, So that they are firmly laterally supported and the interlocking connection between the holder and bit further provide lateral support for the bit so that an extremely rugged construction is attained.

In the modified embodiment shown in Figs. 8 to 13 inclusive, the cutter bit and holder are generally similar to those above described in the preferred embodiment. In this instance, however, the holder projections and bit recesses are modifled to attain additional advantages. A cutter bit like the cutter bit It above described, is of generally triangular formation in side elevation and likewise has its inner inactive cutting portion received in the block socket 6 with its rear side engaging the rear socket wall 8. A holder 3% is received in the block socket at the forward side of the bit and, like the holder l3 of the preferred embodiment, engages at its inner rear side at 371' the rear socket wall. The sides of the cutter bit are formed with relatively wide side recesses 35 opening throu h the front bit face 39 and which, like the bit M of the preferred embodiment, are separated by a relatively narrow web. The side walls at, 40 of the bit recesses are, in this instance, widely diverged and are joined by rearward curved surfaces 4|. The holder, at its outer portion, is longitudinally slotted or grooved at 12 to provide spaced side projections d3, 33 which are received in the bit recesses. The rearward sides of the projections 43 are curved at A l to fit the curved bit surfaces 4| and the rearwardly and outwardly inclined inner surfaces 25 of the holder projections engage the inner forwardly facing walls fill of the bit recesses, as shown in Fig. 8. The holder projections, in this embodiment, serve to support the bit so that there is clearance between the front bit face and the holder, as shown. The set screw [2, when tightened, engages the front side of the holder to force the cutter bit against the rear socket wall. The inner inclined surfaces 45 of the holder projections engaging the inner walls of the recesses hold the the bit against'outward' release from the block socket, and like the preferred embodiment above described, these surfaces tend. to hold, with a wedging action, the holder and bit against outward release even when the set screw becomes slightly loose. The plane front face of the cutter bit terminates in cutting points 46 at the opposite ends of the bit and extending rearwardly and inclined inwardly with respect to the side cutting edges ll, 41 of the cutting points are shearing edges 48 which supplement the cutting edges in the cutting of the coal. The recess walls 40 extend sharply inwardly from the shearing edges 48 to provide cutting clearance. The bit recesses inwardly of the shearing edges 48 provide pockets lzl between the outer walls of the bit recesses and the adjacent end of the bit holder and these pockets are designed to receive cuttings and serve to aid in the conveying of the cuttings back from the korf. To insure proper gauging of the bit, the front cutting face 39 of the bit rests at 55 against the outer edge of the front socket wall, as shown in Fig. 8.

In both embodiments of the invention, the holder is of a width no greater than the width of the cutter bit and by its arrangement in the block socket in advance of the cutter bit, the rear side of the cutter bit, which projects outwardly from the block socket, is free and clear so that movement of the bit through the coal is relatively unimpeded. In both embodiments, the cutter bits are preferably struck from forging dies from an extremely durable and shock-resisting metal and, if desired, the cutting portions may be provided in a known manner with hard faces or hard metal inserts if greater resistance to Wear is desired. It will be observed that in Fig. 7 the side cutting edges of the cutting ends of the bit are shown as curved while in Fig. 11, the side cutting edges are straight, and in both embodiments, the side surfaces of the cutter bit recede rearwardly and inwardly from the cutting edges to provide the needed clearance.

As a result of this invention, there are provided an improved cutter bit of the small, plural pointed, discardable type and an improved one-piece holder whereby the cutter bit may be firmly held and adequately supported in cutting position on a standard chain block in an improved manner. By the provision of the improved cutter bit and holder of the design disclosed, not only is simplicity attained but also there are attained ruggedness and durability comparable to that of a standard single pointed shanked bit. Not only may the bit and holder be-quickly and easily in serted in the block socket but also proper gauging of the bit may be quickly ascertained by the engagernent of the holder or the bit with the exterior surface of the chain block. By recessing the sides of the bit, an improved bit structure is at tained and in one embodiment, supplemental side shearing edges are provided at the outer sides of pockets to aid in cutting, and these pockets receive cuttings to aid in the conveying of the cuttings from the kerf. Other uses and advantages of the invention will be clearly apparent to those skilled in' the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may'be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a cutter chain, a chain block having a right-angle socket normal to the path of travel of the chain, said socket being of substantially rectangular shape in cross section and having a plane rear wall, a plural pointed reversible cutter bit having a body of generally triangular shape in side elevation providing a plane front cutting face terminating in cutting points at the opposite extremities of the bit and the sides of the bit body at its central portion being recessed with the recesses opening forwardly through the plane front face of the bit, said bit received in said block socket with the rear surface of its inner inactive cutting end engaging said rear socket wall and with its active cutting end projecting forwardly and outwardly from the socket, a bit holder received in said socket at the forward side of the bit and coacting with said bit only at the forward side of the latter thereby leaving the rear side of the active cutting end of said bit free and clear and having rear projections at its outer end received in said bit recesses, the inner walls of the bit recesses when the bit is in cutting position in said socket being inclined rearwardly and outwardly with respect to the longitudinal axis of said socket and the lower surfaces of said projections being inclined for engagement with said inclined inner recess Walls for holding said bit in said socket, said rear holder projections received in said bit recesses locking said bit and holder together when said bit and holder are in operative position in said block socket to prevent outward movement of said bit with respect to said holder, and said holder projections being releasable from said bit recesses only upon removal of said bit and holder from said block socket, and adjustable means on the block and engaging the front side of said holder for clamping said bit firmly against said rear socket wall and with said bit firmly locked to said holder, and said inclined surfaces on said bit and said holder tending to hold said bit and said holder in said block socket with a wedging action in the event said adjustable means should become slightly loosened.

2. A cutter bit comprising a body generally tri angular in shape in side elevation and having a plane front cutting face terminating in cuttin points at the opposite ends of the bit and relatively inclined rear surfaces disposed at an obtuse angle, the rear surface of the inner inactive cutting end of the bit when the latter is in cutting position in a socket of a chain block being adapted to engage a rear socket wall, said bit being relatively deeply recessed at its sides with the recesses opening through the front cutting face of the bit and providing substantial walls, the sides of the recesses being relatively inclined and diverging forwardly with the widest parts of the recesses opening through the front bit face, and the outer side walls of said recesses providing shearing edges extending rearwardly and inwardly from the front cutting edges with the recesswalls extending sharply inwardly from said shearing edges to provide cutting clearance.

3. A cutter bit comprising a body generally triangular in shape in side elevation and having a plane front cutting face terminating in cutting points at the opposite ends of the bit and relatively inclined rear surfaces disposed at an obtuse angle, the rear surface of the inner inactive cutting end of the bit when the latter is in cutting position on a socket of a chain block being adapted to engage a rear socket wall, said bit being relatively deeply recessed at its sides with the recesses opening through the cutting face of the bit and providing substantial walls, the sides of the recesses being relatively inclined and diverging forwardly with the widest parts of the recesses opening through the front bit face, and the side walls of said recesses providing shearing edges extending rearwardly and inwardly from the front cutting edges with the recess-walls extending sharply inwardly from said shearing edges to provide cutting clearance, and said recesses inwardly of said shearing edges providing substantial pockets for receiving and conveying cuttings.

4. In a cutter chain, a chain block having a right-angle socket normal to the path of travel of the chain, said socket being of substantially rectangular shape in cross section and having a plane rear wall, a plural pointed reversible cutter bit received in said socket with its back engaging the rear socket wall, said bit having a body of generally triangular shape in side elevation providing a plane front cutting face terminating in cutting points at the opposite extremities of the bit, the sides of the bit body at its central portion being recessed with the recesses opening through the plane front face of the bit to provide a narrow Web between said recesses, the walls of said recesses being relatively inclined to provide abutment surfaces, a bit holder received in said socket at the forward side of the bit and coacting with said bit only at the forward side of the latter, said holder having a shank engaging at its rear side near its inner end the rear socket wall, the outer portion of said holder being vertically slotted to provide spaced rearward side pro-- jections received in said bit recesses with the slot receiving the narrow Web of the bit, the inner surfaces of said side projections being outwardly and rearwardly inclined with respect to the longitudinal axis of said holder and engaging the inner ones of said abutment surfaces on the bit for holding said bit in said socket, said holder side projections received in said bit recesses locking said bit and holder together When said bit and holder are in operative position in said block socket to prevent outward movement of said bit with respect to said holder, and said holder projections being releasable from said bit recesses only upon removal of said bit and holder from said block socket, and adjustable means on the block and engaging the front side of said holder for clamping the back of said bit firmly against said rear socket wall and with said bit firmly locked to said holder, and said inclined surfaces on said bit and holder tending to hold said bit and holder in said block socket with a wedging action in the event said adjustable means should become slightly loosened.

LEON E. SIMMONS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,078,082 Barton Nov. 11, 1913 1,566,304 Bowman Dec. 22, 1925 2,036,327 Fulke Apr. 7, 1926 2,046,023 Lee June 30, 1936 2,183,581 Osgood Dec. 19, 1939 2,229,777 Stephens Jan. 28, 1941 2,387,285 Osgood Oct. 23, 1945 2,389,936 Rupp Nov. 27, 1945 

